Study On The Process Of Aluminium Alloy Cladding Casting

Bimetal cladding materials have been widely used in many fields because of their excellent properties,such as engineering exploration,space industry,civil and war industry.Direct cooling continuous casting is an ideal method for producing bimetal-cladding materials,which can offer low energy consumption,low production costs and higher production efficiency.The effects of casting parameters on the interface characteristics of 4045/3003 aluminum alloys clad ingots were studied.The object is to produce clad ingots with the planar clean interface and high strength interface without porosities and inclusions.Firstly,a mathematical model is built by the commercial software Fluent.The mathematical model can accurately describe the temperature field and the solidification process during the cladding casting.In this paper,the subject researched is the composite billets with the size of ?130mm/?110mm and ?122mm/?110mm,4045 aluminum alloy,whose core layer is AA3003 aluminum alloys and cladding layer is AA4045 aluminum alloys.In this paper,Fluent was used to simulate the temperature field and composite interface during the process of casting in different casting speed,liquid level,contact height and clad thickness.Based on the process parameters of numerical simulation,many casting experiment were done to verify the results in different casting velocity.The macro-morphologies and microstructures of the clad ingots,the temperature distribution and the element distribution in the interface zone were investigated,also the interface bonding strength and Vickers hardness was measured,the conclusions are as follows:(1)By comparing the simulation results,the facts can be concluded:With the increase of the casting speed,contact height and cladding thickness,and the decrease of the liquid level of the AA3003,the temperature of the outer surface of the supporting layer increases.Based on the criterion of the composite effect,the optimal procedure parameters can be summarized:1)The casting velocity is 100mm/min;2)The liquid level of the core-material should be 30mm;3)The contact height should be 30mm;4)The cladding thickness should be 10mm.(2)With the increase of the casting speed,contact height and cladding thickness,and the decrease of the liquid level of the AA3003,the thickness of the diffusion layer is larger,it will be more conducive to the diffusion of alloy elements at the interface,and the metallurgical bonding can be achieved more easily.(3)With the increase of the casting speed,the temperature of the outer surface of the supporting layer increases,the thickness of the supporting layer decreases and the thickness of the diffusion layer becomes larger.When the casting speed is 100mm/min,a wide diffusion layer can be achieved and the bonding interface is straight.Bonding strength test results show that:The samples with the speed of 100mm/min were fractured at the side of AA3003,the tensile strength is 107.5MPa,shear strength reaches about 83MPa,slightly higher than that of AA3003.(4)By studying on the effects of the casting speed,liquid level,contact height and cladding thickness,the optimal procedure parameters of the AA4045/AA3003 cladding casting can be concluded as follows:1)The casting velocity is 100mm/min;2)The liquid level of the core-material should be 30mm;3)The contact height should be 40mm;4)The cladding thickness should be 10mm.